The ex-Barry Sheene
1984 Suzuki RG500 XR45 Racing Motorcycle
Frame no. 2006 Engine no. 11553
Six years out of Grand Prix racing, Suzuki returned in 1973 with a roadster-based TR500 twin for works rider Jack Findlay and, after what was essentially an interim season, was ready to take on the MV 'four' and Yamaha's TZ500. The Hamamatsu firm already had plenty of experience of square four engines in the form of the defunct RZ63 250, and this compact layout was revived for its new premier-class racer - the RG500. Like its quarter-liter predecessor, the RG500 employed disc valve induction and separate geared-together crankshafts driving a six-speed transmission via an intermediate gear. Over-square bore/stroke dimensions of 56x50.5mm were used and a maximum output of 90bhp at 10,500rpm claimed. This state-of-the-art power unit was housed in a conventional tubular-steel duplex-loop frame.
In 1974 Britain's rising star Barry Sheene, winner of the '73 FIM Formula 750 Championship on a Suzuki TR750, rode his works RG500 to a debut second place in the season-opening French Grand Prix behind Phil Read's MV. Inevitably though, there were teething problems, chiefly associated with engine seizures and wayward high-speed handling. Sheene ended the season sixth in the World Championship.
The RG500 was revised for 1975 and now produced around 100bhp. Sheene's season was curtailed by a sickening high-speed crash at Daytona in March, but he bounced back to take his and the RG500's first 500cc World Championship victory at Assen later in the year. A second win, at Anderstorp, helped him to sixth in the Championship again.
Suzuki altered the RG's engine for 1976, adopting the 'classic' dimensions of 54x54mm bore/stroke and fitting seven-port cylinder barrels. Power increased only marginally, but more importantly the design was now fully sorted and reliable, enabling Sheene to win five of the six World Championship rounds he contested and finish second in the other, bringing Suzuki its first title in Grand Prix racing's premier class. The 'square' RG500 engine was retained for 1977, Sheene becoming champion again, but heavily revised for the following season when it appeared in XR22 guise with stepped cylinder pairs - the front lower than the rear - and twin crankshafts. The claimed maximum power output was now around 120-125bhp.
Despite these improvements, the combination of Kenny Roberts and Yamaha proved good enough to deprive Suzuki of 500cc World Championship honours for the next three years. Not until 1981, when Italian Marco Lucchinelli triumphed aboard the Roberto Gallina-entered RG500, did the crown return to Hamamatsu. Gallina was rewarded with full factory Suzukis for 1982, securing back-to-back titles when Lucchinelli's replacement Franco Uncini emerged victorious. By 1983 the pace of RG500 development had slackened and the bike was no longer competitive with its Honda and Yamaha rivals. In its day though, the RG500 was the class of the field. Offered for public sale from 1976, it provided talented privateers with a competitive mount at the highest level, and Jack Middleburgh's 1981 British Grand Prix-winning RG500 remains the last entirely private entry to win a 500c World Championship round.
This RG500 XR45 was used by Barry Sheene in 1984, his final season before retirement. He used two machines that year, one of which was fitted with a Harris frame and other non-standard parts, while the other - the machine offered for sale here - remained in standard factory specification. Sheene finished in eight rounds of the 1984 World Championship on his way to sixth place at the season's end, his best result being third place in South Africa. The machine is presented in excellent original condition and the vendor advises us that the engine has recently been checked and is ready to use. A unique opportunity to purchase the last factory Suzuki raced by the late, great World Champion.